<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script>
			var a=10;
			{
				var a=20;
				console.log(a)
			}
			console.log(a)
			
			let b=10;
			{
				 b=20;
				console.log(b)
			}
			console.log(b)
			
			const x=10;
			
			/* var e670=(x,y)=>{js语句} */
			
		</script>
	</head>
	<body>
	</body>
</html>
